1. Field of the Invention
The present invention relates to agricultural implements, and specifically to an apparatus for supporting a tillage implement and providing compaction for said implement.
2. Description of the Prior Art
Compaction immediately after planting is very beneficial to crop yields. When soil is packed around the newly-planted seed, moisture is retained in the soil by expelling the air in the soil. As a result, the seed does not dry out and can draw water up for growth. Besides increasing the crop yield, compaction also conserves valuable field moisture and reduces topsoil erosion by both water and wind. Additionally, when the tillage and compaction functions are combined on one implement, fuel and labor costs are reduced substantially by elimination of the need for a second separate compaction pass after the seeds have been sown.
Various compaction devices for packing the soil after tilling are well known in the prior art. Often, such devices are pivotally mounted behind a tilling disk or shoe which is supported from a frame secured to the rear of a tractor. Examples of devices of this type are shown in the following United States patents:
______________________________________ Inventor U.S. Pat. No. Issue Date ______________________________________ Tanke 2,685,384 08/03/54 Padrick 2,734,439 02/14/56 Nelson 2,745,330 05/15/56 Brinton 2,756,702 07/31/56 Olson 2,947,372 08/02/60 Oehler et al 3,055,322 09/25/62 Rawlinson 3,137,073 06/16/64 Gatzke et al 3,450,074 06/17/69 Bradley 4,112,857 09/12/78 Yeager 4,239,086 12/16/80 ______________________________________
Other tillage and compaction implements have been designed to be drawn behind a tractor. In these devices, separate transport wheels are provided to support the implement (including the tillers and press wheels) when raised for turning or transport to a different location. In operation, the tillers and press wheels are lowered so that the press wheels track a path behind the tillers to pack the soil. Examples of such devices are found in the following United States patents:
______________________________________ Inventor U.S. Pat. No. Issue Date ______________________________________ Ackley 3,060,872 10/30/62 Reaves 3,138,125 06/23/64 Krumholz 3,701,327 10/31/72 Moore 4,196,679 08/08/80 Pollard 4,273,057 06/16/81 ______________________________________
Some implements in the prior art have compaction wheels that also act as support wheels for the implement. One such device is shown in U.S. Pat. No. 4,135,457, granted to Willis on Jan. 23, 1979. In Willis, each packing wheel is adjusted individually to vary the height of the coulter directly in front of it. The Willis device is not a plurality of coulters and press wheels secured together, but is a singular unit adapted for attachment to a transverse tow bar secured behind a tractor.
The corn planter shown in U.S. Pat. No. 731,658, granted to Barry on June 23, 1903, also has supporting wheels which serve as packing wheels. This device has a pair of pivotal wheel mounts, with each wheel mount having a pair of wheels shafted on the same axle to track behind the tillers. Because the wheel mounts are pivotally mounted, each pair of wheels can pivot laterally with respect to the implement to facilitate corn planting on uneven terrain.
Some crops can be efficiently grown in closely spaced rows. Implements for tilling, seeding and packing the soil over the seeds for such crops are shown in U.S. Pat. No. 3,033,135, granted to Gouin on May 8, 1962 and U.S. Pat. No. 738,816, granted to Kindsvater on Sept. 15, 1903. Gouin shows an agricultural implement wherein all the packer wheels are aligned on a common axis behind the tiller shoes. The mounting support for the packer wheels is pivotally mounted on a longitudinal axis so that the mounting support and packer wheels thereon can, to a limited extent, pivot laterally with respect to the frame of the implement. The tiller shoes can be raised or lowered from the frame so the packing wheels provide both compaction and transport support for the implement. In the Kindsvater implement, each press wheel is individually mounted behind a tiller and a spring is positioned on each press wheel mount to urge the press wheel thereon toward the ground. Thus, each press wheel moves independently of the other wheels to follow the contours of the ground. These press wheels do not provide support for the Kindsvater implement during transport or operation, and though independently mounted, the wheels are all shafted on a substantially common axis laterally behind the implement.
When packing wheels are closely spaced, such as those shown in the Gouin and Kindsvater patents, soil can collect in the close spaces between the wheels (especially when the soil is moist) and diminish their effectiveness. To this end, various mud cleaners have been provided in the prior art, such as those shown in U.S. Pat. No. 3,682,252, granted to Gates on Aug. 8, 1972. The problem is not fully alleviated by such devices, however.
Another method of compaction is to pull a large metal coil over the soil, either attached behind a tillage implement or in a separate pass. Such coils do not support the tillage implement, and thus are not heavy enough to compact the soil effectively. Additionally, compaction by such coils is not specifically directed to the area of soil containing newly-planted seed.
None of the prior art devices discussed above show an implement providing both tillage and compaction wherein the compaction wheels provide support for the weight of the implement and are able to independently follow the contours of the ground. In addition, where prior art compaction wheels are provided for closely spaced crops, the packer wheels have the problems of mud collection which creates uneven and inefficient packing.